I started this Field Notes midway through August and finished it in the final week of October. In general I have been quite happy with it. It has been truly bulletproof with fountain pen inks but oddly enough, I have found its performance lacking with more conventional types of pens like the Retro 51. I have experienced a lot of skipping when using the Schmidt refills which is disappointing. Regardless, fountain pens are what matters to me and they work great.
I've just started a new pocket book that may be "The one book to rule them all." Let me introduce the Hobonichi Memo Pad. This notebook is filled with 48 stitch bound pages of Tomoe River paper with a 3.7 mm grid on it. Each page is perforated to allow you to cleanly tear it out. Since the book is made with Tomoe River paper, it is only 2 mm thick and just marginally wider than a Field Notes book. Oh, and did I mention that the books are half of the price of Field Notes? (before you have them shipped from Japan)
I'm going to try this one for a couple of months to see how it does over the long run, but I'm pretty stoked about the possibilities.